This invention relates in general to on-line testing systems and, in particular, to a conveying system which controls the movements of articles through a testing or monitoring station.
More specifically this invention relates to a conveyor which may be readily interposed in an existing conveying line to control the movement of articles through a monitoring station and to remove those articles which vary from a predetermined test standard.
The problems encountered when conveying materials or articles through a production facility, and inspecting these materials as they pass through the production line or processing stations, are both many and varied. Attempted solutions to these problems have been as varied as the products being manufactured or the processes being employed. While this invention has general application in many production or processing systems, for convenience of illustration it will be described with reference to its use in the food processing industry which requires high speed and inexpensive transporting systems to handle canned goods as they are being processed.
In the processing of food stuffs, various comestibles or food products are prepared and a measured amount placed into a suitable container to be packaged in a manner which will preserve the food stuffs until such time as they are used by a consumer. Quality control and product purity are stringent requirements or standards which are imposed on the food processing industry to guard the health of the consumer. During the food packaging operation stringent quality control measures are taken to insure the integrity of both the product and the packaging. For example, in canning food stuffs the product is prepared and the cans are sterilized such that after a measured amount of food stuffs have been placed into the can and the can sealed, a negative pressure or vacuum is produced in order to maintain freshness of the product and prohibit the growth of oxygen requiring bacteria. If after such processing the vacuum within the can is lost, the can becomes a potential health hazard and causes serious economic loss to a distributor when the contents spoil during shipping or storage. Such cans frequently explode or expel their contents throughout the case in which they are packaged contaminating the other containers within the casing as well as surrounding materials.
Since testing of the cans to insure that a proper vacuum has been maintained is so important, various systems have been devised to monitor the cans to insure that a proper vacuum is present. Many of these prior art systems require that the cans be diverted from the processing line to an "off-line" monitoring station whereat the cans are tested and then placed back on line for further processing, such as labelling. While these systems have been somewhat satisfactory, an obvious problem associated with such systems is the diverting of the cans off the line to the testing station, and the reintroduction from the testing station back onto the processing line. As is well known to those skilled in this art, when cans are removed from the on-line conveying system and diverted to and from the testing station to go back on line, a substantial loss of time is incurred as well as frequent interruptions of the processing procedures due to jams occasioned at the diverty stations.